There are constantly growing demands of people for types of services which can be supported by terminal device along with the popularization of smart phones, and in view of this, a new work item has been introduced by the 3rd Generation Partnership Project (3GPP) under the discussion of the Long Tem Evolution-Advanced (LTE-A) Release 11 (Rel-11), i.e., the Enhancements for Diverse Data Applications (eDDA), which is intended to enhance the existing technologies in the LTE-A system, thereby to improve the performance of the LTE-A system, to save signaling/resource overheads, to guarantee experiences of subscribers and power saving of the terminal, and other objects, in view of types of services which can be supported nowadays by the terminal devices tending to be diversified. This technology is applicable to an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) and a User Equipment (UE). In order to attain these objects, both the UE and network sides need to obtain state information of each other.
A background service and an instant message (IM) service are two types of services at the highest priority investigated in the eDDA scenario. These two services have gained popular attention among various enterprises in real applications due to their low amount of traffic and variable burst data packets. Particularly the background service typically refers to a service in an inactive state has some low amount of data traffic to maintain a connection, and the IM service typically refers to a service with small but temporarily burst/frequent data packets including mobile QQ, Fetion, etc. In order to enable the network side to obtain a service characteristic and know a preference of a subscriber (for example, whether the UE prefers a power-saving mode or another mode with a better experience of the subscriber at that time) instantly and effectively, the introduction of a mechanism for reporting eDDA assistance information at the UE side has been suggested at the radio access network Layer 2 (RAN 2). eDDA assistance information is reported at the UE side primarily for the purpose of assisting the network side in configuring the UE with a more appropriate radio resource parameter including a Discontinuous Reception (DRX) parameter or another Radio Resource Control (RRC) parameter. When there is a change to the state of the UE (e.g., a change to its preference), the UE can report the changed information again to the network side. The network side will issue an indicator to the UE to indicate whether eDDA assistance information reporting is supported in the current cell. The UE can report eDDA assistance information to an evolved Node B (eNB) only if an indicator for allowing the reporting is detected.
In the existing application scenario, when UE moves in communication from a coverage area of one base station to a coverage of another base station or there is a drop in quality of communication due to external interference, the UE has to be handed over from the current communication link to an idle communication link of another cell, or the UE has to be handed over from the current communication link to a communication link of another cell for the purpose of load balancing. In this case, there has been absent in the prior art a solution to obtaining by the target base station the eDDA assistance information of the UE.